Copper alloys with dispersed metal nitrides and method of manufacture

Abstract

Spray cast alloys having reduced porosity and increased ductility are provided as well as a process for the manufacture of the alloys. An effective amount of a reactive metal which reacts with the spray casting atmosphere but not with the desired alloy is dissolved into the alloy prior to spray casting. Preferred reactive metals readily form a nitride which is finely dispersed throughout the spray cast alloy.

We claim: 
     
       1. A spray cast metal alloy having substantially reduced porosity formed by atomization with a gas which is generally nonreactive with copper and copper alloys, consisting essentially of: a predominantly copper matrix; and   a second phase dispersed throughout said matrix, said second phase consisting essentially of an additive combined with said gas.   
     
     
       2. The spray cast alloy of claim 1 wherein said atomizing gas is nitrogen and said second phase is a finely dispersed nitride. 
     
     
       3. The spray cast alloy of claim 2 wherein said additive is selected from the group consisting of aluminum, silicon, titanium, chromium or mixtures thereof. 
     
     
       4. A spray cast metal alloy having substantially reduced porosity consisting essentially of: a predominantly copper matrix; and   a second phase finely dispersed throughout said matrix, said second phase consisting essentially of the nitride of an additive selected from the group consisting of aluminum, silicon, titanium and chromium or mixtures thereof wherein the concentration of said additive is from about 0.01 weight percent to about 1.0 weight percent.   
     
     
       5. The spray cast alloy of claim 4 wherein the concentration of said additive is from about 0.1 weight percent to about 0.5 weight percent. 
     
     
       6. The spray cast alloy of claim 4 wherein said additive is aluminum. 
     
     
       7. The spray cast alloy of claim 4 wherein said predominantly copper matrix has an electrical conductivity above about 50% IACS and said second phase dispersion is selected from the group consisting of aluminum nitride, silicon nitride, titanium nitride, chromium nitride and mixtures thereof. 
     
     
       8. The spray cast alloy of claim 7 wherein said predominantly copper matrix has a composition 97.5% by weight copper, 2.35% by weight iron, 0.03% by weight phosphorus and 0.12% by weight zinc. 
     
     
       9. The spray cast alloy of claim 4 wherein said predominantly copper matrix is a phosphor bronze and said second phase dispersion is selected from the group consisting of aluminum nitride, silicon nitride, titanium nitride, chromium nitride and mixtures thereof. 
     
     
       10. The spray cast alloy of claim 9 wherein said phosphor bronze has the composition 94.9% by weight copper, 5% by weight tin and 0.1% by weight phosphorous.